/*
 *
 * Copyright 2015 gRPC authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#include <iostream>
#include <memory>
#include <string>

#include "absl/flags/flag.h"
#include "absl/flags/parse.h"

#include <grpcpp/grpcpp.h>

#ifdef BAZEL_BUILD
#include "examples/protos/helloworld.grpc.pb.h"
#else
#include "helloworld.grpc.pb.h"

#endif

ABSL_FLAG(std::string, target, "localhost:50051", "Server address");

using grpc::Channel;
using grpc::ClientContext;
using grpc::Status;
using helloworld::Greeter;
using helloworld::HelloReply;
using helloworld::HelloRequest;

class GreeterClient
{
 public:
	GreeterClient(std::shared_ptr<Channel> channel)
		: stub_(Greeter::NewStub(channel))
	{
	}

	// Assembles the client's payload, sends it and presents the response back
	// from the server.
	std::string SayHello(const std::string& user)
	{
		// Data we are sending to the server.
		HelloRequest request;
		request.set_name(user);

		// Container for the data we expect from the server.
		HelloReply reply;

		// Context for the client. It could be used to convey extra information to
		// the server and/or tweak certain RPC behaviors.
		ClientContext context;

		// The actual RPC.
		Status status = stub_->SayHello(&context, request, &reply);

		// Act upon its status.
		if (status.ok())
		{
			return reply.message();
		}
		else
		{
			std::cout << status.error_code() << ": " << status.error_message()
					  << std::endl;
			return "RPC failed";
		}
	}

 private:
	std::unique_ptr<Greeter::Stub> stub_;
};

int main(int argc, char** argv)
{
	absl::ParseCommandLine(argc, argv);
	// Instantiate the client. It requires a channel, out of which the actual RPCs
	// are created. This channel models a connection to an endpoint specified by
	// the argument "--target=" which is the only expected argument.
	std::string target_str = absl::GetFlag(FLAGS_target);
	// We indicate that the channel isn't authenticated (use of
	// InsecureChannelCredentials()).
	GreeterClient greeter(
		grpc::CreateChannel(target_str, grpc::InsecureChannelCredentials()));
	std::string user("world");
	std::string reply = greeter.SayHello(user);
	std::cout << "Greeter received: " << reply << std::endl;

	return 0;
}
